All of lore.kernel.org
 help / color / mirror / Atom feed
From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Peter Zijlstra <peterz@infradead.org>,
	Masami Hiramatsu <mhiramat@kernel.org>,
	Josh Poimboeuf <jpoimboe@redhat.com>,
	Frederic Weisbecker <frederic@kernel.org>,
	Joel Fernandes <joel@joelfernandes.org>,
	Andy Lutomirski <luto@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Namhyung Kim <namhyung@kernel.org>,
	"Frank Ch. Eigler" <fche@redhat.com>
Subject: [PATCH 08/16 v3] ftrace: Allow function_graph tracer to be enabled in instances
Date: Fri, 24 May 2019 23:16:41 -0400	[thread overview]
Message-ID: <20190525031746.431969203@goodmis.org> (raw)
In-Reply-To: 20190525031633.811342628@goodmis.org

From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>

Now that function graph tracing can handle more than one user, allow it to
be enabled in the ftrace instances. Note, the filtering of the functions is
still joined by the top level set_ftrace_filter and friends, as well as the
graph and nograph files.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 include/linux/ftrace.h               |  1 +
 kernel/trace/ftrace.c                |  1 +
 kernel/trace/trace.h                 | 12 +++++
 kernel/trace/trace_functions.c       |  7 +++
 kernel/trace/trace_functions_graph.c | 65 +++++++++++++++++-----------
 kernel/trace/trace_selftest.c        |  2 +-
 6 files changed, 62 insertions(+), 26 deletions(-)

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 906f7c25faa6..766c565ba243 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -752,6 +752,7 @@ extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace, struct fgraph
 struct fgraph_ops {
 	trace_func_graph_ent_t		entryfunc;
 	trace_func_graph_ret_t		retfunc;
+	void				*private;
 };
 
 /*
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 35c79f3ab2f5..6719a6cae67b 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -6226,6 +6226,7 @@ __init void ftrace_init_global_array_ops(struct trace_array *tr)
 	tr->ops = &global_ops;
 	tr->ops->private = tr;
 	ftrace_init_trace_array(tr);
+	init_array_fgraph_ops(tr);
 }
 
 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func)
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 982f5fa8da09..40b0471194bf 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -313,6 +313,9 @@ struct trace_array {
 #ifdef CONFIG_FUNCTION_TRACER
 	struct ftrace_ops	*ops;
 	struct trace_pid_list	__rcu *function_pids;
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+	struct fgraph_ops	*gops;
+#endif
 #ifdef CONFIG_DYNAMIC_FTRACE
 	/* All of these are protected by the ftrace_lock */
 	struct list_head	func_probes;
@@ -930,6 +933,9 @@ extern int __trace_graph_entry(struct trace_array *tr,
 extern void __trace_graph_return(struct trace_array *tr,
 				 struct ftrace_graph_ret *trace,
 				 unsigned long flags, int pc);
+extern void init_array_fgraph_ops(struct trace_array *tr);
+extern int allocate_fgraph_ops(struct trace_array *tr);
+extern void free_fgraph_ops(struct trace_array *tr);
 
 #ifdef CONFIG_DYNAMIC_FTRACE
 extern struct ftrace_hash *ftrace_graph_hash;
@@ -1023,6 +1029,12 @@ print_graph_function_flags(struct trace_iterator *iter, u32 flags)
 {
 	return TRACE_TYPE_UNHANDLED;
 }
+static inline void init_array_fgraph_ops(struct trace_array *tr) { }
+static inline int allocate_fgraph_ops(struct trace_array *tr)
+{
+	return 0;
+}
+static inline void free_fgraph_ops(struct trace_array *tr) { }
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 
 extern struct list_head ftrace_pids;
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index b611cd36e22d..9b45ede6ea89 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -68,6 +68,12 @@ int ftrace_create_function_files(struct trace_array *tr,
 	if (ret)
 		return ret;
 
+	ret = allocate_fgraph_ops(tr);
+	if (ret) {
+		kfree(tr->ops);
+		return ret;
+	}
+
 	ftrace_create_filter_files(tr->ops, parent);
 
 	return 0;
@@ -78,6 +84,7 @@ void ftrace_destroy_function_files(struct trace_array *tr)
 	ftrace_destroy_filter_files(tr->ops);
 	kfree(tr->ops);
 	tr->ops = NULL;
+	free_fgraph_ops(tr);
 }
 
 static int function_trace_init(struct trace_array *tr)
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 2ae21788fcaf..064811ba846c 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -77,8 +77,6 @@ static struct tracer_flags tracer_flags = {
 	.opts = trace_opts
 };
 
-static struct trace_array *graph_array;
-
 /*
  * DURATION column is being also used to display IRQ signs,
  * following values are used by print_graph_irq and others
@@ -127,7 +125,7 @@ static inline int ftrace_graph_ignore_irqs(void)
 int trace_graph_entry(struct ftrace_graph_ent *trace,
 		      struct fgraph_ops *gops)
 {
-	struct trace_array *tr = graph_array;
+	struct trace_array *tr = gops->private;
 	struct trace_array_cpu *data;
 	unsigned long flags;
 	long disabled;
@@ -241,7 +239,7 @@ void __trace_graph_return(struct trace_array *tr,
 void trace_graph_return(struct ftrace_graph_ret *trace,
 			struct fgraph_ops *gops)
 {
-	struct trace_array *tr = graph_array;
+	struct trace_array *tr = gops->private;
 	struct trace_array_cpu *data;
 	unsigned long flags;
 	long disabled;
@@ -267,15 +265,6 @@ void trace_graph_return(struct ftrace_graph_ret *trace,
 	local_irq_restore(flags);
 }
 
-void set_graph_array(struct trace_array *tr)
-{
-	graph_array = tr;
-
-	/* Make graph_array visible before we start tracing */
-
-	smp_mb();
-}
-
 static void trace_graph_thresh_return(struct ftrace_graph_ret *trace,
 				      struct fgraph_ops *gops)
 {
@@ -293,25 +282,53 @@ static void trace_graph_thresh_return(struct ftrace_graph_ret *trace,
 		trace_graph_return(trace, gops);
 }
 
-static struct fgraph_ops funcgraph_thresh_ops = {
-	.entryfunc = &trace_graph_entry,
-	.retfunc = &trace_graph_thresh_return,
-};
-
 static struct fgraph_ops funcgraph_ops = {
 	.entryfunc = &trace_graph_entry,
 	.retfunc = &trace_graph_return,
 };
 
+int allocate_fgraph_ops(struct trace_array *tr)
+{
+	struct fgraph_ops *gops;
+
+	gops = kzalloc(sizeof(*gops), GFP_KERNEL);
+	if (!gops)
+		return -ENOMEM;
+
+	gops->entryfunc = &trace_graph_entry;
+	gops->retfunc = &trace_graph_return;
+
+	tr->gops = gops;
+	gops->private = tr;
+	return 0;
+}
+
+void free_fgraph_ops(struct trace_array *tr)
+{
+	kfree(tr->gops);
+}
+
+__init void init_array_fgraph_ops(struct trace_array *tr)
+{
+	tr->gops = &funcgraph_ops;
+	funcgraph_ops.private = tr;
+}
+
 static int graph_trace_init(struct trace_array *tr)
 {
 	int ret;
 
-	set_graph_array(tr);
+	tr->gops->entryfunc = trace_graph_entry;
+
 	if (tracing_thresh)
-		ret = register_ftrace_graph(&funcgraph_thresh_ops);
+		tr->gops->retfunc = trace_graph_thresh_return;
 	else
-		ret = register_ftrace_graph(&funcgraph_ops);
+		tr->gops->retfunc = trace_graph_return;
+
+	/* Make gops functions are visible before we start tracing */
+	smp_mb();
+
+	ret = register_ftrace_graph(tr->gops);
 	if (ret)
 		return ret;
 	tracing_start_cmdline_record();
@@ -322,10 +339,7 @@ static int graph_trace_init(struct trace_array *tr)
 static void graph_trace_reset(struct trace_array *tr)
 {
 	tracing_stop_cmdline_record();
-	if (tracing_thresh)
-		unregister_ftrace_graph(&funcgraph_thresh_ops);
-	else
-		unregister_ftrace_graph(&funcgraph_ops);
+	unregister_ftrace_graph(tr->gops);
 }
 
 static int graph_trace_update_thresh(struct trace_array *tr)
@@ -1297,6 +1311,7 @@ static struct tracer graph_trace __tracer_data = {
 	.print_header	= print_graph_headers,
 	.flags		= &tracer_flags,
 	.set_flag	= func_graph_set_flag,
+	.allow_instances = true,
 #ifdef CONFIG_FTRACE_SELFTEST
 	.selftest	= trace_selftest_startup_function_graph,
 #endif
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index 8639d278b6b2..facd5d1c05e7 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -770,7 +770,7 @@ trace_selftest_startup_function_graph(struct tracer *trace,
 	 * to detect and recover from possible hangs
 	 */
 	tracing_reset_online_cpus(&tr->trace_buffer);
-	set_graph_array(tr);
+	fgraph_ops.private = tr;
 	ret = register_ftrace_graph(&fgraph_ops);
 	if (ret) {
 		warn_failed_init_tracer(trace, ret);
-- 
2.20.1



  parent reply	other threads:[~2019-05-25  3:18 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-25  3:16 [PATCH 00/16 v3] function_graph: Rewrite to allow multiple users Steven Rostedt
2019-05-25  3:16 ` [PATCH 01/16 v3] function_graph: Convert ret_stack to a series of longs Steven Rostedt
2019-05-28  9:50   ` Joel Fernandes
2019-05-28 12:58     ` Steven Rostedt
2019-05-28 17:46       ` Joel Fernandes
2019-05-25  3:16 ` [PATCH 02/16 v3] fgraph: Use BUILD_BUG_ON() to make sure we have structures divisible by long Steven Rostedt
2019-05-25  3:16 ` [PATCH 03/16 v3] fgraph: Have the current->ret_stack go down not up Steven Rostedt
2019-05-25  3:16 ` [PATCH 04/16 v3] function_graph: Add an array structure that will allow multiple callbacks Steven Rostedt
2019-05-25  3:16 ` [PATCH 05/16 v3] function_graph: Allow multiple users to attach to function graph Steven Rostedt
2019-05-25  3:16 ` [PATCH 06/16 v3] function_graph: Remove logic around ftrace_graph_entry and return Steven Rostedt
2019-05-25  3:16 ` [PATCH 07/16 v3] ftrace/function_graph: Pass fgraph_ops to function graph callbacks Steven Rostedt
2019-05-25  3:16 ` Steven Rostedt [this message]
2019-05-25  3:16 ` [PATCH 09/16 v3] ftrace: Allow ftrace startup flags exist without dynamic ftrace Steven Rostedt
2019-05-25  3:16 ` [PATCH 10/16 v3] function_graph: Have the instances use their own ftrace_ops for filtering Steven Rostedt
2019-05-25  3:16 ` [PATCH 11/16 v3] function_graph: Add "task variables" per task for fgraph_ops Steven Rostedt
2019-05-25  3:16 ` [PATCH 12/16 v3] function_graph: Move set_graph_function tests to shadow stack global var Steven Rostedt
2019-05-25  3:16 ` [PATCH 13/16 v3] function_graph: Move graph depth stored data " Steven Rostedt
2019-05-25  3:16 ` [PATCH 14/16 v3] function_graph: Move graph notrace bit " Steven Rostedt
2019-05-25  3:16 ` [PATCH 15/16 v3] function_graph: Implement fgraph_reserve_data() and fgraph_retrieve_data() Steven Rostedt
2019-05-25  3:16 ` [PATCH 16/16 v3] function_graph: Add selftest for passing local variables Steven Rostedt

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190525031746.431969203@goodmis.org \
    --to=rostedt@goodmis.org \
    --cc=akpm@linux-foundation.org \
    --cc=fche@redhat.com \
    --cc=frederic@kernel.org \
    --cc=joel@joelfernandes.org \
    --cc=jpoimboe@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=luto@kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=mhiramat@kernel.org \
    --cc=mingo@kernel.org \
    --cc=namhyung@kernel.org \
    --cc=peterz@infradead.org \
    --cc=tglx@linutronix.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.